Test 1 Flashcards
1
Q
Georges Cuvier (1769-1832)
A
- fossils resemble but are not exactly the same as modern species
- many past species are extinct
2
Q
James Hutton
A
- observable processes produce small changes that accumulate over time
- the earth must be old
3
Q
William Smith
A
- different rock layers contain distinct fossils
4
Q
Jean Lamarck
A
- proposed a full-blown theory of evolution
- life driven from simple to complex
- complex species descended from microbes
- microbes continually generated spontaneously
- adaptation occurs through inheritance of acquired changes
- proposed a view of evolution that questioned the then popular idea that species did not change
- idea that changes do take place in animals over long periods of time, specifically through the use of organs and appendages
- popular example is the long necks of giraffes
5
Q
In the 1800s, what three individuals proposed explanations for biological evolution?
A
Jean Lamarck, Charles Darwin, and Alfred Russel Wallace
6
Q
Charles Darwin
A
- Invited to serve as unofficial naturalist for HMS Beagle in 1831
- observed similarities and differences among organisms and compare them on the mainland and islands
- theory of natural selection
- wanted to amass a wealth of evidence before presenting his idea
- published a book
- sexual selection
- genetic drift
7
Q
Alfred Russel Wallace
A
- expedition to Amazon river
- observed variations in organisms that engaged same questions that Darwin posed
- sent Darwin his theory, to which to Darwin’s shock, nearly replicated Darwin’s own
- Darwin reported his and Wallace’s work in a joint presentation
8
Q
Homologous trait
A
Similar because of inheritance from a common ancestor
9
Q
Sexual selection
A
Selection for traits that provide a mating advantage
10
Q
Genetic drift
A
Change in frequency of traits due to chance events
11
Q
Mendel
A
- studied hereditary in a garden of peas
12
Q
Which scientists showed how natural selection could operate in a Mendelian world?
A
Ronald Fisher, JBS Haldane, and Sewall Wright
13
Q
Fisher, Haldane, and Wright left what major project open for later biologists?
A
To explain the language of genes, what species are and how they originate
14
Q
Theodosius Dobzhansky
A
- interested in discovering the genetics that determined the differences between populations of a species
- “The Modern Synthesis”
15
Q
Lord Kelvin
A
- disputed Darwin
- proposed earth was no more than 20 million years old based on the temperature of rocks
16
Q
What indicates that the earth is 4.6 billion years old?
A
Radiometric dating
17
Q
What allows us to learn about extinct species?
A
Fossils
18
Q
Biomarker
A
Distinctive molecules only produced through biological activity
19
Q
What was used to infer types of plants eaten?
A
C13/C14 ratio
20
Q
Thales and Anaximander
A
Proposed explanations for life’s origins and gradual changes
21
Q
Earths oldest materials
A
4.3 billion year old zircon crystals
22
Q
Archean era (3.8-2.5bya)
A
- earliest signs of life
- origin of multicellularity a major transition in history of life
- oldest fossils of multicellular life
- earliest fossils of algae
23
Q
Cryogenian (850-635mya)
A
- succession of incredibly harsh ice ages
- Snowball earth
- life consisted of tiny organisms - microscopic ancestors of fungi, plants, animals, and kelps evolved during this time
24
Q
Ediacaran (635-545mya)
A
- also known as the Vendian
- final stage of Pre-Cambrian time
- all life was soft-bodied
- diverse and unique animals dominated the oceans
- worlds first ever burrowing animals - found fossils of the burrows
25
Cambrian (545-495mya)
- explosion of abundant and diverse life forms
- shells
- sea still very much the center of licit activity
26
Ordovician (495-443mya)
- few animals explored margins of land, but nothing colonized
- majority of life still in seas
- began with shallow, warm seas but the end of the period experienced a 500,000 year long ice age, triggered by the drift of the supercontinent, Gondwana, to the south polar regions
- ended with a mass extinction
- first terrestrial plant and fungal life
- early plants resembled mosses and liverworts
- fungi appear
27
Ordovician-Silurian mass extinction
- third largest extinction in earths history
- had two peak dying times
- some 85% of sea life was wiped out
- ice age blamed
- huge ice sheet in the Southern Hemisphere caused climate change and a fall in sea level, and messed with the chemistry of the oceans
28
Silurian (443-417mya)
- reefs - new type of ecosystem for marine life
- host of tabulate and rugose corals, Crinoids, and sponges
- extensive seas
- bony fish made their first appearance
- plants became more established
- first wetland habitats
- first terrestrial animal life
29
First terrestrial animal life
Silurian
30
Devonian (417-354mya)
- Age of Fishes
- sea surface temps averaged 30C
- growth rings from corals provided evidence that there were more than 365 days in the year back then
- first terrestrial vertebrates
- oldest fossils of tetrapods
31
Late Devonian mass extinction
- 3/4 of all species on earth died out
- much of sea bed became devoid of oxygen
- out of bounds for anything except bacteria
- changes in sea level, asteroid impacts, climate change, and new kinds of plants messing with the soil have all been blamed for these extinctions
32
Carboniferous (354-290 mya)
- highest atmospheric oxygen levels the earth has ever experienced
- evolution of first reptiles
- plants grew and died at such a great rate that they eventually became coal
- Coal Measures after its proliferation of coal-bearing rocks
- started off warm, but temp dropped and polar regions plunged into an ice age because of its lush coal forests
- two epochs - Mississippian and Pennsylvanian
33
Permian (290-248 mya)
- started with ice age
- ended with the most devastating mass extinction earth has ever experienced
- two mass extinctions occurred
- continents finally coalesced into one supercontinent, Pangaea
- oxygen levels plummeted from 35% to around 15%
34
Permian mass extinction
- The Great Dying
- Permian-Triassic extinction event
- up to 96% of marine species and 70% of terrestrial vertebrate species became extinct
- only known mass extinction of all insects
- so much biodiversity was lost
- earlier phase likely due to gradual environmental change
- latter phase has been argued to be due to a catastrophic event
35
Triassic (205-142 mya)
- life on earth took a while to recover
- heat, vast desert, and warm seas
- first mammals and dinosaurs evolved
- Pangaea began to break apart
- ended as it had begun, with an extinction
36
Triassic-Jurassic mass extinction
- climate change, flood basalt eruptions, and an asteroid impact have been blamed
- plants were not so badly affected
- vacated terrestrial ecological niches, allowing dinosaurs to assume the dominant roles
- evolution of mammals
- mammals evolved from synapsids
37
Jurassic (205-142 mya)
- life was quick to recover
- host the most diverse range of organisms that earth had seen yet
- first birds
- continental break gave rise to the sea that became Atlantic Ocean
- ocean floor that formed at this time is the oldest surviving on the planet
38
Cretaceous (142-65 mya)
- ended with most famous mass extinction - the one that killed the dinosaurs
- much of what we know as dry land was underwater
39
K/T extinction
- famed for death of dinosaurs
- suggested thy the declines was due to flood basil eruptions effecting the worlds climate, combined with drastic falls in sea level
- then a huge asteroid or comet struck the seabed near the Yucatan Peninsula in Mexico
40
Paleocene (65-54.8 mya)
- dense forests and evolutionary experiments
- more mammals and birds to evolve
- India and Asia collided
- at the end, an abrupt ride in temp across the planet made the climate much wetter and caused a sea level rise
- diversification of mammals
- whales, bats, and primates
41
Eocene (54.8-33.7 mya)
- began as time of global warming
- trees grew even in polar regions
- be me cooler and drier
- mass of rocks thrust up to form the Himalayas
- Africa was an island
- many species of grass evolved
42
Oligocene (33.7-23.8 mya)
- global cooling that would shift earths climate to one where glaciers were present and ice ages were possible
- grasslands began to expand and forests shrank
- open landscape
- many fast running prey and predator species arose as a result
43
Miocene (23.8-5.3 mya)
- apes arose and diversified
- ancestors of humans had split away from ancestors of chimps to follow their own evolutionary path
- kelp forests made their first appearance and became one of earths most productive ecosystems
44
Pliocene (5.3-2.6 mya)
- north and South America had been drifting ever closer and gap was sealed
- ice at North Pole became permanent, grassland and tundra thrived
45
Pleistocene (2.6mya-11.7tya)
- glaciers came and went, series of ice ages
- dust storms would have been a lot more common
- our species evolved
46
Holocene (11.7tya-present)
- current geological epoch
- started when glaciers began to retreat
- man kinds demand for timber and agricultural land grew
- still in an ice age - indicated of ice caps at the poles
- planet is just in an interglacial phase
